Loudness Units relative to Full Scale: the standard measurement for perceptual loudness used in broadcast and streaming normalization.
LUFS (Loudness Units relative to Full Scale) is a unit of measurement for perceptual audio loudness that accounts for how the human ear responds to different frequencies and loudness levels over time. It is the standard metric used by streaming platforms and broadcast regulators to normalize playback loudness, with most streaming platforms targeting an integrated loudness of approximately -14 LUFS.
Why it matters
When a streaming platform normalizes all tracks to the same LUFS target, a track mastered louder than that target gets turned down rather than playing back louder than others. DJs who understand LUFS can anticipate how tracks will behave under gain normalization and avoid setting gain incorrectly when switching between tracks mastered to very different loudness levels.
In practice
A track mastered at -6 LUFS will be attenuated significantly by a streaming platform targeting -14 LUFS, meaning it will arrive in your DJ software at a lower output level than a track mastered at -14 LUFS. If you mix tracks from streaming sources alongside purchased files that have not been normalized, compensate with the channel gain trim rather than the master output.
